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particles was the concept of Symmetry . Nature points the way to many of its underlying principles through the existence of various symmetries. Quarks The quark scheme was suggested by the symmetries in the way the many mesons and baryons seemed to be arranged in families. Theorists Gell-Mann
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- 1.1 Handedness in the Equation of Motion
- 1.2 Chiral Interactions
- 1.3 Fundamental Strong Interaction
- 1.5 Mass and Electric Charge
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- 1.6 Hypercharge Interaction of the Standard Model
- 1.7 Higgs Mechanism
- 1.8 Program of Study
- 1.9 Exercises
A massless particle with nonzero intrinsic spin travels at the speed of light and has a definite handedness as defined by the sign of the dot product of the momentum and spin. The handedness of a massless particle, of which there are two possible values, is invariant and effectively decouples the elementary particles into two types, left-handed and...
The existence of an interaction is reflected in the quantum numbers of the elementary par-ticles. We introduce here a particular type of chiral interaction, one in which left-handed particle states can be transformed into one another in a manner similar to a rotation. However, unlike a spatial rotation, the chiral interaction acts on an internal sp...
We now consider the force that leads to the formation of protons and neutrons, and is ultimately responsible for nuclear forces. This force is the fundamental strong interaction and, similar to the chiral interaction, is an interaction that acts on an internal space. In this case, the internal space is larger and has a smallest nontrivial represent...
While mass and electric charge are second nature from classical physics, they are highly nonobvious quantities in the elementary particles. In other words, their origin is believed to be linked to the properties of the physical vacuum rather than an inherent quantity that one would assign based on first principles, as explained below. The “poor ass...
up d down v e electron neutrino charm s strange v μ muon neutrino top b bottom v τ tau neutrino H Higgs boson
The Standard Model is a theory that solves the paradox of the “hidden symmetry” of the chiral interaction. To restore the indistinguishability of components of a chiral doublet, the Standard Model eliminates electromagnetism as an elementary interaction of mass-less fermions. The road to reintroducing electomagnetism as an interaction of massive fe...
The central concept of the Standard Model is that the properties of the physical vacuum do not have the same symmetries as the fundamental interactions. This notion seems absurd at first, but physical examples of such systems, such as low-temperature super-conductivity, clearly demonstrate such behavior in nonvacuous environments. Indeed, in a supe...
The Higgs mechanism of the Standard Model is a great leap beyond the notion of an empty vacuum and symmetry-preserving interactions. Indeed, the timeline of when the universe developed a vacuum filled with a symmetry-breaking condensate is not clear. Perhaps the most trying part of studying elementary particle physics is the lack of di-rect evidenc...
Fundamental interactions. What are the interactions described by the Standard Model in a symmetry- preserving vacuum? Ignore the Higgs interactions. What Standard Model interactions in part (a) are unaffected by the reduced sym-metries of the physical vacuum? Elementary fermions. The right-handed up-type leptons are unusual fermion components in...
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Elementary-particle physics deals with the fundamental constituents of mat-ter and their interactions. In the past several decades an enormous amount of experimental information has been accumulated, and many patterns and sys-tematic features have been observed.
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The aim of this book is to present fundamental concepts in particle physics. This includes topics such as the theories of quantum electrodynamics, quantum chromodynamics, weak interactions, Feynman diagrams and Feynman rules, important conservation laws and symmetries pertaining to particle dynamics, relativistic field
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Overview of elements of the “Standard Model'' of particle physics. • Fermions: Quarks and Leptons. • Gauge Bosons and Forces. Higgs boson. • Brief history of Particle physics, discovery of fundamental particles. - Basic tools used in particle physics: • Reminder about the concepts used in the course and equations related to
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Concepts in Particle Physics Subjects, concepts to be discussed in the lectures include: 1 The Standard Model is a theory ofquantum fields. 2 Observablesrelevant to high-energy particle physics: cross sections, decay rates, ... 3 The Standard Model is mostly defined by itssymmetries. 4 It has manyparameters: in particular, can we ...
The Standard Model of particle physics provides the most accurate description of nature at the subatomic level. It is based on the quantum theory of fields and has been tested with exquisite precision. In the quantum field theory there is one field for each type of particle – matter particles and force particles. 1 Matter particles.
